JAVA实现微信支付功能

深碍√TFBOYSˉ_ 2022-04-02 19:28 262阅读 0赞

一，问题

这两天，需要接入微信支付功能。由于我是公众号开发，因此，我选择的微信支付方式是JSAPI支付方式。

二，解决方案

2.1 配置微信平台

①配置微信公众平台

登录微信公众平台=》公众号设置=》功能设置=》网页授权域名

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②配置微信商家平台

产品中心=》开发配置

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Rhb3RpYW8wMTk5_size_16_color_FFFFFF_t_70 2]

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2.2 后台代码的实现

JSAPI官方文档：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=9_1

①先去官方下载SDK，并导进项目中

地址：https://pay.weixin.qq.com/wiki/doc/api/jsapi.php?chapter=11_1

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Rhb3RpYW8wMTk5_size_16_color_FFFFFF_t_70 4]

②准备好11个参数

appid：商家平台ID。在微信的平台上有
    body：商品描述。
    mch_id：商户ID。在微信的平台上有
    nonce_str：随机字符串，UUID就好了。
    openid：用户标识。因为这边是用户已经登录成功了。所以在session中就能拿到。
    out_trade_no：商户订单号
    spbill_create_ip：终端IP。这个可以从请求头中拿到
    total_fee：支付金额。单位是分。
    trade_type：交易类型。这里我填JSAPI
    notify_url：通知地址。就是用户支付成功之后，微信访问你的哪个接口，跟你传递支付成功的相关信息。

sign：签名。这个签名它是由上面的10个参数计算得出的。

③源码  
sendPay类：

import java.io.IOException;
    import java.io.InputStream;
    import java.math.BigDecimal;
    import java.net.URLEncoder;
    import java.util.HashMap;
    import java.util.Map;
    import java.util.UUID;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.apache.http.auth.AUTH;
    import org.hamcrest.core.Is;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.jc.util.wxPay.WXPayUtil;
    import com.sun.xml.internal.fastinfoset.Encoder;
    
    import controller.AuthUtil;
    import net.sf.json.JSONObject;
    
    @Controller
    @RequestMapping("/pay")
    public class sendPay {
     
    	/**
    	 * @Description 微信浏览器内微信支付/公众号支付(JSAPI)
    	 * @param request
    	 * @param code
    	 * @return Map
    	 */
    	@RequestMapping(value = "orders")
    	public @ResponseBody Map<String, String> orders(HttpServletRequest request, HttpServletResponse response) {
    		try {
    			 
    			String openId = "用户的openid";
    
    			// 拼接统一下单地址参数
    			Map<String, String> paraMap = new HashMap<String, String>();
    			// 获取请求ip地址
    			String ip = request.getHeader("x-forwarded-for");
    			if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    				ip = request.getHeader("Proxy-Client-IP");
    			}
    			if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    				ip = request.getHeader("WL-Proxy-Client-IP");
    			}
    			if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
    				ip = request.getRemoteAddr();
    			}
    			if (ip.indexOf(",") != -1) {
    				String[] ips = ip.split(",");
    				ip = ips[0].trim();
    			}
    
    			paraMap.put("appid", AuthUtil.APPID); // 商家平台ID
    			paraMap.put("body", "纯情小店铺-薯条"); // 商家名称-销售商品类目、String(128)
    			paraMap.put("mch_id", AuthUtil.MCHID); // 商户ID
    			paraMap.put("nonce_str", WXPayUtil.generateNonceStr()); // UUID
    			paraMap.put("openid", openId);
    			paraMap.put("out_trade_no", UUID.randomUUID().toString().replaceAll("-", ""));// 订单号,每次都不同
    			paraMap.put("spbill_create_ip", ip);
    			paraMap.put("total_fee", "1"); // 支付金额，单位分
    			paraMap.put("trade_type", "JSAPI"); // 支付类型
    			paraMap.put("notify_url", "用户支付完成后，你想微信调你的哪个接口");// 此路径是微信服务器调用支付结果通知路径随意写
    			String sign = WXPayUtil.generateSignature(paraMap, AuthUtil.PATERNERKEY);
    			paraMap.put("sign", sign);
    			String xml = WXPayUtil.mapToXml(paraMap);// 将所有参数(map)转xml格式
    
    			// 统一下单 https://api.mch.weixin.qq.com/pay/unifiedorder
    			String unifiedorder_url = "https://api.mch.weixin.qq.com/pay/unifiedorder";
    
    			System.out.println("xml为：" + xml);
    
    			// String xmlStr = HttpRequest.sendPost(unifiedorder_url,
    			// xml);//发送post请求"统一下单接口"返回预支付id:prepay_id
    
    			String xmlStr = HttpRequest.httpsRequest(unifiedorder_url, "POST", xml);
    
    			System.out.println("xmlStr为：" + xmlStr);
    
    			// 以下内容是返回前端页面的json数据
    			String prepay_id = "";// 预支付id
    			if (xmlStr.indexOf("SUCCESS") != -1) {
    				Map<String, String> map = WXPayUtil.xmlToMap(xmlStr);
    				prepay_id = (String) map.get("prepay_id");
    			}
    
    			Map<String, String> payMap = new HashMap<String, String>();
    			payMap.put("appId", AuthUtil.APPID);
    			payMap.put("timeStamp", WXPayUtil.getCurrentTimestamp() + "");
    			payMap.put("nonceStr", WXPayUtil.generateNonceStr());
    			payMap.put("signType", "MD5");
    			payMap.put("package", "prepay_id=" + prepay_id);
    			String paySign = WXPayUtil.generateSignature(payMap, AuthUtil.PATERNERKEY);
    			payMap.put("paySign", paySign);
    			//将这个6个参数传给前端
    			return payMap;
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    		return null;
    	}
    
    	/**
    	 * @Title: callBack
    	 * @Description: 支付完成的回调函数
    	 * @param:
    	 * @return:
    	 */
    	@RequestMapping("/notify")
    	public String callBack(HttpServletRequest request, HttpServletResponse response) {
    		// System.out.println("微信支付成功,微信发送的callback信息,请注意修改订单信息");
    		InputStream is = null;
    		try {
    
    			is = request.getInputStream();// 获取请求的流信息(这里是微信发的xml格式所有只能使用流来读)
    			String xml = WXPayUtil.InputStream2String(is);
    			Map<String, String> notifyMap = WXPayUtil.xmlToMap(xml);// 将微信发的xml转map
    			
    			System.out.println("微信返回给回调函数的信息为："+xml);
    			
    			if (notifyMap.get("result_code").equals("SUCCESS")) {
    				String ordersSn = notifyMap.get("out_trade_no");// 商户订单号
    				String amountpaid = notifyMap.get("total_fee");// 实际支付的订单金额:单位 分
    				BigDecimal amountPay = (new BigDecimal(amountpaid).divide(new BigDecimal("100"))).setScale(2);// 将分转换成元-实际支付金额:元
    
    				/*
    				 * 以下是自己的业务处理------仅做参考 更新order对应字段/已支付金额/状态码
    				 */
    				System.out.println("===notify===回调方法已经被调！！！");
    				
    			}
    			
    			// 告诉微信服务器收到信息了，不要在调用回调action了========这里很重要回复微信服务器信息用流发送一个xml即可
    			response.getWriter().write("<xml><return_code><![CDATA[SUCCESS]]></return_code></xml>");
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			if (is != null) {
    				try {
    					is.close();
    				} catch (IOException e) { 
    					e.printStackTrace();
    				}
    			}
    		}
    		
    		return null;
    	}
    
    }

HttpRequest类：

import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStream;
    import java.io.PrintWriter;
    import java.net.URL;
    import java.net.URLConnection;
    import java.util.List;
    import java.util.Map;
    
    import javax.net.ssl.HttpsURLConnection;
    
    public class HttpRequest {
    	/**
    	 * 向指定URL发送GET方法的请求
    	 * 
    	 * @param url
    	 *            发送请求的URL
    	 * @param param
    	 *            请求参数,请求参数应该是 name1=value1&name2=value2 的形式。
    	 * @return URL 所代表远程资源的响应结果
    	 */
    	public static String sendGet(String url, String param) {
    		String result = "";
    		BufferedReader in = null;
    		try {
    			String urlNameString = url + "?" + param;
    			System.out.println(urlNameString);
    			URL realUrl = new URL(urlNameString);
    			// 打开和URL之间的连接
    			URLConnection connection = realUrl.openConnection();
    			// 设置通用的请求属性
    			connection.setRequestProperty("accept", "*/*");
    			connection.setRequestProperty("connection", "Keep-Alive");
    			connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
    			// 建立实际的连接
    			connection.connect();
    			// 获取所有响应头字段
    			Map<String, List<String>> map = connection.getHeaderFields();
    			// 遍历所有的响应头字段
    			for (String key : map.keySet()) {
    				System.out.println(key + "--->" + map.get(key));
    			}
    			// 定义 BufferedReader输入流来读取URL的响应
    			in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
    			String line;
    			while ((line = in.readLine()) != null) {
    				result += line;
    			}
    		} catch (Exception e) {
    			System.out.println("发送GET请求出现异常！" + e);
    			e.printStackTrace();
    		}
    		// 使用finally块来关闭输入流
    		finally {
    			try {
    				if (in != null) {
    					in.close();
    				}
    			} catch (Exception e2) {
    				e2.printStackTrace();
    			}
    		}
    		return result;
    	}
    
    	/**
    	 * 向指定 URL 发送POST方法的请求
    	 * 
    	 * @param url
    	 *            发送请求的 URL
    	 * @param param
    	 *            请求参数,请求参数应该是 name1=value1&name2=value2 的形式。
    	 * @return 所代表远程资源的响应结果
    	 */
    	public static String sendPost(String url, String param) {
    		PrintWriter out = null;
    		BufferedReader in = null;
    		String result = "";
    		try {
    			URL realUrl = new URL(url);
    			// 打开和URL之间的连接
    			URLConnection conn = realUrl.openConnection();
    			// 设置通用的请求属性
    			conn.setRequestProperty("accept", "*/*");
    			conn.setRequestProperty("connection", "Keep-Alive");
    			conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
    			// 发送POST请求必须设置如下两行
    			conn.setDoOutput(true);
    			conn.setDoInput(true);
    			// 获取URLConnection对象对应的输出流
    			out = new PrintWriter(conn.getOutputStream());
    			// 发送请求参数
    			out.print(param);
    			// flush输出流的缓冲
    			out.flush();
    			// 定义BufferedReader输入流来读取URL的响应
    			in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
    			String line;
    			while ((line = in.readLine()) != null) {
    				result += line;
    			}
    		} catch (Exception e) {
    			System.out.println("发送 POST 请求出现异常！" + e);
    			e.printStackTrace();
    		}
    		// 使用finally块来关闭输出流、输入流
    		finally {
    			try {
    				if (out != null) {
    					out.close();
    				}
    				if (in != null) {
    					in.close();
    				}
    			} catch (IOException ex) {
    				ex.printStackTrace();
    			}
    		}
    		return result;
    	}
    
    	/**
    	 * post请求并得到返回结果
    	 * 
    	 * @param requestUrl
    	 * @param requestMethod
    	 * @param output
    	 * @return
    	 */
    	public static String httpsRequest(String requestUrl, String requestMethod, String output) {
    		try { 
    			URL url = new URL(requestUrl);
    			HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
    			connection.setDoOutput(true);
    			connection.setDoInput(true);
    			connection.setUseCaches(false);
    			connection.setRequestMethod(requestMethod);
    			if (null != output) {
    				OutputStream outputStream = connection.getOutputStream();
    				outputStream.write(output.getBytes("UTF-8"));
    				outputStream.close();
    			}
    			// 从输入流读取返回内容
    			InputStream inputStream = connection.getInputStream();
    			InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");
    			BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
    			String str = null;
    			StringBuffer buffer = new StringBuffer();
    			while ((str = bufferedReader.readLine()) != null) {
    				buffer.append(str);
    			}
    			bufferedReader.close();
    			inputStreamReader.close();
    			inputStream.close();
    			inputStream = null;
    			connection.disconnect();
    			return buffer.toString();
    		} catch (Exception ex) {
    			ex.printStackTrace();
    		}
    
    		return "";
    	}
    }

AuthUtil类

import java.io.IOException;
    
    import org.apache.http.HttpEntity;
    import org.apache.http.HttpResponse;
    import org.apache.http.client.ClientProtocolException;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.impl.client.DefaultHttpClient;
    import org.apache.http.util.EntityUtils;
    
    import net.sf.json.JSONObject;
    public class AuthUtil {
    	public static final String APPID = "平台ID";
    	public static final String APPSECRET = "平台密钥";
    	public static final String MCHID = "商家ID";
    	public static final String PATERNERKEY = "商家密钥";
    	
    	
    	public static JSONObject doGetJson(String url) throws ClientProtocolException, IOException {
    		JSONObject jsonObject = null;
    		// 首先初始化HttpClient对象
    		DefaultHttpClient client = new DefaultHttpClient();
    		// 通过get方式进行提交
    		HttpGet httpGet = new HttpGet(url);
    		// 通过HTTPclient的execute方法进行发送请求
    		HttpResponse response = client.execute(httpGet);
    		// 从response里面拿自己想要的结果
    		HttpEntity entity = response.getEntity();
    		if (entity != null) {
    			String result = EntityUtils.toString(entity, "UTF-8");
    			jsonObject = jsonObject.fromObject(result);
    		}
    		// 把链接释放掉
    		httpGet.releaseConnection();
    		return jsonObject;
    	}
    }

2.3 前端的实现

这是只用一个jsp页面来做测试

<%@ page language="java" contentType="text/html; charset=UTF-8"
    	pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <script type="text/javascript" src="./js/jquery-1.11.0.min.js"></script>
    <title>微信支付JSP</title>
    </head>
    <body> 
    	<input type="button" value="进行微信支付" id="payId">
    
    	<script type="text/javascript">
    	
    		$(function(){
    			var appId,timeStamp,nonceStr,package,signType,paySign; 
    			
    			$("#payId").click(function(){
    				pay();
    			});
    			
    			//去后台拿六个参数
    			function pay(){   
    				var url = "http://localhost:8082/WeChat/pay/orders";
    			  	$.get(url,function(result) {	
    		  				appId = result.appId;
    						timeStamp = result.timeStamp;
    						nonceStr = result.nonceStr;
    						package = result.package;
    						signType = result.signType;
    						paySign = result.paySign;
    						
    						if (typeof WeixinJSBridge == "undefined") {
    							if (document.addEventListener) {
    								document.addEventListener('WeixinJSBridgeReady',
    										onBridgeReady, false);
    							} else if (document.attachEvent) {
    								document.attachEvent('WeixinJSBridgeReady',
    										onBridgeReady);
    								document.attachEvent('onWeixinJSBridgeReady',
    										onBridgeReady);
    							}
    							alert("请在微信上进行支付操作！");
    							onBridgeReady();
    						} else { 
    							onBridgeReady();
    						}
    					});
    				}
    			//去微信那边发起支付请求
    			function onBridgeReady(){
    				
    				 alert("appId:"+appId+" "+"timeStamp:"+timeStamp+" "+"nonceStr:"+nonceStr+" "+"package:"+package+" "+"signType:"+signType+" "+"paySign:"+paySign+" ");
    				
    				  WeixinJSBridge.invoke( 'getBrandWCPayRequest', {
    					  "appId":appId,     //公众号名称,由商户传入     
    			          "timeStamp":timeStamp,         //时间戳,自1970年以来的秒数     
    			          "nonceStr":nonceStr, //随机串     
    			          "package":package,     
    			          "signType":signType,         //微信签名方式：     
    			          "paySign":paySign //微信签名 
    			         }, 
    			         function(res){      
    			      	   if(res.err_msg == "get_brand_wcpay_request:ok" ) {
    			                 //alert('支付成功');
    			                 console.log("支付成功");
    			                 //支付成功后跳转的页面
    			             }else if(res.err_msg == "get_brand_wcpay_request:cancel"){
    			            	 alert('支付取消');
    			             }else if(res.err_msg == "get_brand_wcpay_request:fail"){
    			            	 alert('支付失败');
    			            	 
    			            	 alert(JSON.stringify(res));
    			            	 
    			                 WeixinJSBridge.call('closeWindow');
    			             } //使用以上方式判断前端返回,微信团队郑重提示：res.err_msg将在用户支付成功后返回ok,但并不保证它绝对可靠。
    			   });    
    			}
    		})
    </script>
    
    </body>
    </html>

三，总结

虽然第一次看官方文档很乱，信息量很多，但仔细总结一下，其实就下面这点流程而已。

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最后，很感谢网上一位大哥分享了他的经验。  
大哥链接：`https://blog.csdn.net/javaYouCome/article/details/79473743`

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